The delays in the destruction of Syria’s chemical weapons stockpile and the possible emergence of hitherto unknown weapons is not prompting Israel to rethink its defence programme against unconventional weapons.

The Israeli government decided three months ago to cease the distribution of gas masks to the entire population.

The Organisation for the Prohibition of Chemical Weapons (OPCW) and the United Nations announced on Tuesday that 88 per cent of Syria’s chemical weapon materials had “been removed from or destroyed in-country”. The updated assessment came after months of delays.

Now the OPCW believes that the arsenal could be completely dismantled by the end of this month, even before the original July 30 deadline.

Western intelligence organisations have voiced scepticism over whether the Syrians would stick to the 12-month deadline it agreed to last year and are still waiting for verification of the OPCW-UN reports.

Meanwhile, there have been reports of new chemical attacks, involving bombs filled with chlorine, carried out by the Syrian military. Chlorine is not on the list of chemicals proscribed by the Chemical Weapons Convention that Syria signed last year.

While Syria would be allowed to continue holding chlorine under the agreement brokered by the Russian government, using such weapons would still constitute a war crime.

Although British, French and US intelligence agencies are still investigating reports that chlorine bombs have been used, the evidence that has emerged so far — including indications that these bombs have been dropped from the air — leaves little doubt.

While the situation in Syria is being continuously monitored in Israel, the view remains that the regime’s military infrastructure has been degraded to such a degree that it now lacks the delivery platforms to launch its remaining chemical stockpile.

Israelis also think it unlikely that President Bashar Assad would invite upon himself the massive retribution that would come should he fire chemical bombs at Israeli targets.